Link filament spools card on dashboard to FilamentDB (new tab)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

app/routers/ui.py

@@ -1,3 +1,4 @@
+import os
 import uuid as _uuid
 from pathlib import Path
 
@@ -42,6 +43,7 @@ def dashboard(request: Request, db: Session = Depends(get_db)):
             PrintJob.status.in_([JobStatus.queued, JobStatus.printing])
         ).count(),
         "total_filaments": sum(r.get("rolls_in_stock", 0) for r in get_stock()),
+        "filamentdb_url": os.environ.get("FILAMENTDB_URL", ""),
         "recent_jobs": db.query(PrintJob).order_by(PrintJob.created_at.desc()).limit(5).all(),
     })